PROJECT SUMMARY The coronavirus disease 2019 (COVID-19) pandemic poses unique threats to individuals with opioid use disorder (OUD).1,2 They are likely to be particularly vulnerable to COVID-19 and the public health measures (i.e., social distancing) to control the disease.3,4 Specifically, individuals with OUD in remission may be at substantial risk for return to opioid use given disruptions in addiction treatment, such as medications for OUD (MOUD). In addition, stress due to social distancing, finances, loss of employment or housing may be a trigger for return to use. COVID-19 may result in changes in illicit opioid supply and diverted buprenorphine and methadone as programs and clinicians follow federal recommendations and provide patients with more take home doses of methadone (increasing risk for overdose and diversion) and longer prescriptions of buprenorphine. Separately, there is concern that OUD-related stigma, lack of usual source of care, and potential consequences of a positive test (e.g., housing situation), individuals with OUD may be less likely to seek a COVID-19 test even when clinically recommended. Importantly, all of these factors may vary widely based on geography. To provide urgent insights on the potential impact of COVID-19 on individuals with OUD in four US cities, and informed by prior research,5,6 we will leverage the >700 patients enrolled in Project ED- Health (CTN-0069) and research infrastructure7 to reach individuals with OUD. Specifically, we will attempt to contact all 738 individuals who were enrolled in Project ED-Health, at one of our four participating emergency departments (ED) located in New York, NY; Baltimore, MD; Seattle, WA; and Cincinnati, OH, to participate in a follow-up one time telephone-based survey. We will collect self-reported data on the impact of the COVID-19 epidemic on opioid use and treatment and COVID-19 symptoms and testing. We will triangulate these data with an electronic survey of medical directors and site-Principal Investigators at each site to capture data on the impact of COVID-19 on ED presentations and experiences of patients with OUD. This work will be conducted by a team of investigators that has robust experiences in developing and implementing surveys,8-12 linking self-reported and electronic health record data,13-15 and conducting longitudinal research with individuals with OUD.16-20 Thus, among a geographically diverse (Northeast, Mid-Atlantic, Midwest, West Coast) sample of individuals with OUD, we seek to characterize the impact of the COVID-19 pandemic on (Aim 1) OUD treatment (engagement and access to MOUD), drug use, drug supply, and overdose risk, (Aim 2) COVID-19 related symptoms and testing, and (Aim 3) ED leadership reports of the presentation of patients with OUD to the ED, ED-based buprenorphine prescribing practices, and community treatment options. These time sensitive data are urgently needed to begin to understand the impact of COVID-19 among individuals with OUD to directly inform clinical interventions and policies.